Citroen XM Forum

Hello all. It's great to be a XM owner again we have missed having one but so far it's not going smoothly. Are you ready for this? I hope so

We are in Suffolk in the UK and have bought a XM 2.1 TD auto mk 1 on an L reg. Nice car got a bargain & very pleased with it. Needs a few bits sorting broken seat runners , glove box etc but overall a very nice condition car with massive paper trail of work done and full service history. It was an old man's pride and joy. It is the 6th XM that we have owned over the years the last one being at least 10 years ago. That is where the niceness ends. This little beauty is now being a sod.

It drove really well for the first 8 days, no issues. Then it began. It would start and run but 5 seconds of driving and it would slowly drop the revs, stall and die. It would eventually re-start and then drive for 30 seconds or less before repeating. It would do this 2/3/4 times and then it would drive all day long with no issues, stopping for shops, fuel etc no problem.

Then it decided it was having a fuel leak from the injector pump. Diesel was leaking in the engine bay and evidence seen. Problem going to be sorted we thought. It went to the garage. Gaskets changed, problem remained. One by one things were tested and replaced, fuel pipes, fuel filter, primer, fuel return valve, fuel sender gasket. Cured? No..... it is still doing the same thing but no longer any diesel smell or visible leaks. Leave it ticking over and it's normally ok, but try and run it harder and it runs and stalls. It didn't always start easily either and a new battery has helped. Sounds like a fuel/air problem but where?

Yesterday we collected it from the garage, it needed to be out of the way as they are not a citroen specialist and don't really know where to turn next. Of course it started first time then ran perfectly and drove home the 8 miles with no issues. It had been basking in the sun all day and was clearly in a good mood. I tried it later that evening and it ran, spluttered, stalled and went to sleep. The car was then left overnight to think about it's behaviour and to contemplate it's future!

We joined and looked on this forum to seek advice and whether anyone else had encountered similar problems and conquered.

Whilst browsing there have been several points that have shown up as potential suspects -

1 = the glow plug relay not performing as it should

2 = the fuel system getting air in the system somewhere. One of the pieces of advice on here suggested leaving it overnight and then pushing the primer and if it took more than a couple of pushes before going hard, then this indicated air in the system or a blocked fuel tank breather . So today I pushed the primer and after 8 or more pushes it eventually went hard, fuel could be heard swirling up into the filter . I left it a couple of minutes and then it was soft again. It took several pumps before it was hard again. That sounds suspect to me. Am I right in thinking it should remain pressured? If I am correct then it appears that the fuel is flowing straight back out again. So I primed the pump and quickly jumped in, started the car and it started easily and the best it has done so far. I left it a couple of minutes without priming and it's back to struggling to start again. Lots of turning over before firing and then doing the run and stall as before.

3 = Fuel tank breather being blocked - obviously this is located on the fuel tank but where? top, middle or bottom, RHS, LHS? Is it easy to access and to clear? Could it be the air is trapped in the system and priming is transferring the fuel and air back and forth? I primed the pump and removed the fuel cap and there was noticeable suction on the cap, it was very tight.

Are we heading in the right direction with any of these? Am I missing something obvious or maybe not so obvious?

Any help would be very much appreciated from the experts on here with the knowledge that we don't have. We never had this with either of the other 2 diesels and we did many thousands of miles in them without any major hiccup.

Thanks for reading

Best regards

Paul

The first two culprits for air in fuel are the primer head itself and also the fuel heater on the side of the cylinder head..

Remove the fuel heater from fuel line.. And try again.. I'll. Get a picture of the area its in so you know where I'm talking about.

Here's two shots of the fuel heater.. One clearly shows the fuel in pipe bypassing it and going directly to the fuel filter housing..
The heater is well know for causing issues..

Nice colour. Not sure about the xantia wheel trims though..

citroenxm wrote: ↑

Tue Apr 21, 2020 8:11 pm

Here's two shots of the fuel heater.. One clearly shows the fuel in pipe bypassing it and going directly to the fuel filter housing..

_20200421_210816.JPG

_20200421_210844.JPG

The heater is well know for causing issues..

That is brilliant thank you I will have a look tomorrow in the daylight.
Am I right in thinking that pump remain primed and firm ? Because if it should then it's definitely not doing that . Cheers Paul

citroenxm wrote: ↑

Tue Apr 21, 2020 8:12 pm

Nice colour. Not sure about the xantia wheel trims though..

Yes, they are very suspect but it has 4 which are all the same and they are working doing as they should so they are far down the list of problems at the moment

After an overnight stop. The primer should go solid after at least one and a half pushs.. Any more then that the fuel is draining back from air getting in..

citroenxm wrote: ↑

Tue Apr 21, 2020 8:36 pm

After an overnight stop. The primer should go solid after at least one and a half pushs.. Any more then that the fuel is draining back from air getting in..

OK thanks once again. I shall look at both possible causes then. It's a new primer but I guess that doesn't rule it out. I was convinced there was an air leak sound when I primed it the first time but I couldn't hear it the second time. It needs further investigation. I shall return Cheers Paul

The fuel filter (if a Purflux, with the primer button on top) contains not only the main filter element in the bowl, but a micro-filter in the head. It is located under the exit (pump side) banjo bolt, and is a small brass widget. These can get clogged, and cause fuel starvation, less likely when engine bay (and fuel) is hot.

There are also tiny non-return valves (two, iirc) under the inlet side banjo bolt, to prevent fuel going backwards into the tank.

If you take these small widgets out, do make a sketch of where they go (and which way round!) as you go.

As said, fuel heater is a thing to bypass. Check the large filter bowl O-ring and its groove (in the filter head) for cleanliness, no damage, and good fit.